Apparatus for molding curved pipe

ABSTRACT

A machine for molding a pipe bend from concrete or the like includes a mold having an arcuate tubular mold cavity defining the outer contours of the pipe bend, an arcuate core mounted for swinging movement into and out of one end of the mold cavity along the axis of the latter to define therewith an annular space and a rotatable bell form for shaping the inner surface of one end of the molded pipe bend.

United States Patent [191 Brown Mar. 12, 1974 APPARATUS FOR MOLDING CURVED PIPE [76] Inventor: Howard P. Brown, 104 S. Nash St.,

Starkville, Miss. 39759 [22] Filed: Aug. 19, 1970 [21] Appl. No.: 65,090

[52] US. Cl 249/63, 249/1'51, 249/177,

' 425/456, 425/468 [51] Int. Cl. B29c 11/00 [58 Field of Search 25/39, 36, 30 R, 126;

[56] References Cited UNITED STATES PATENTS Smith 25/30 R Knight 249/144 X Groot 249/144 A Primary Examiner-Robert D. Baldwin Assistant Examiner.lohn McQuade Attorney, Agent, or Firm-Gold & Litman Fishburn 571 ABSTRACT A machine for molding a pipe bend from concrete or the like includes a mold having an arcuate tubular mold cavity defining the outer contours of the pipe bend, an arcuate core mounted for swinging movement into and out of one end of the mold cavity along the axis of the latter to define therewith an annular 'spaceand a rotatable bell form for shaping the inner surface of one end of the molded pipe bend.

2 Chin 15,2 Drawing Figures APPARATUS FOR MOLDING CURVEI) PIPE This invention relates to a machine for casting or molding a curved length of pipe, such as a 90 bend. In particular it relates to a machine for making concrete pipe bends, the machine being of the type having a fixed mold cavity which defines the exterior contours of the pipe bend and a pivoted curved core which swings into and out of the mold cavity through of the latter.

A known form of machine is disclosed in expired US. Pat. No. 2,508,293. In that machine there was provided a fixed curved outer form and a rotating packer head which was withdrawn, while rotating, from the curved form along the axis of the latter to thereby pack the concrete and shape the pipe bend. The rotating packer head was carriedat one end of a non-rotating, curved arm of lesser diameter than the packer head, and the arm was pivotally mounted so as to be swingable into and out of the fixed form. A flexible driven shaft extended axially through the arm for rotating the packer one end head.

According to the principles of the present invention there is provided a concrete pipe bend machine having a pivoted butnon-rotating curved core which is held stationary within an outer form during the casting of a pipe bend. This arrangement has the advantage of accurately holding the concrete in place until it is set up sufficiently to retain its shape.

The invention will be further understood from the following detailed description of an illustrativeembodiment taken with the drawings in which:

FIG. 1 is a vertical sectional view of a concrete pipe bend machine embodying the principles of the present invention, and

FIG. 2 is a side elevational view, partly in section and partly broken away, looking from the left side of FIG. 1.

The machine illustrated in the drawings includes as its major elements an outer form 10 or mold which defines the outer contours of a concrete pipe bend 12 being cast therein, an inner core 14 which defines substantially the entirebore of the pipe bend l2 and a bell form 16 which defines an enlarged end of the bore. A main frame 18 of open box-like construction is disposed around the outer form 10 to provide support for the components of the machine.

The outer form ldefines a tubular bore or cavity of circular cross section which is arcuately curved to form the exterior contours of the desired pipe bend, the illustrated bend being 90. The form will normally be constructed in two or more longitudinal sections, constructed of sheet metal for example, releasably secured together so that the sections may be disassembled to permit removal of the completedpipe bend 12. The upper end of the outer form 10 is removably secured of the form 10 from the frame 18. The ends of the shaft are supported within sleeves 32 which are fixed to the frame 18. A collar 34 secured to each end of the shaft by a set screw 35 retains the shaft 30 in the mounting sleeves 32. During a casting operation the plate 26 is held in the illustrated position by any suitable latch arrangement, such as cam type locking arms 36 which secure the plate 26 to the frame 18.

The core 14, which is complementary to but of lesser cross section than the arcuate mold cavity defined by the form 10, .is mounted for rotation about the shaft 30 so as to be movable into and out of the form 10 along the axis of curvature of the mold. cavity. The shaft 30 is therefore disposed coaxially with this axis of curvature as will be apparent from inspection of FIG. 1. In the illustrated embodiment the mounting for the core 14 includes an ann 38 fixed at its upper end to a sleeve 40 which is carried on the shaft 30. The arm 38 extends downwardly through an aperture 42 in the plate 26 and terminates opposite the lower end of the outer form 10. The lower end of the core 14 is attached to the arm 38 in any suitable manner as by means of studs 44 embedded in the core 14 and projecting through the arm 38 and secured with nuts 46. The arm 38 can-be latched in its down position by means of any convenient latch arrangement such as a notched flat spring 48. The material of construction for the core 14 may be concrete, as in the illustrated embodiment, metal or plastic. The diameter of the core 14 is uniform throughout its length, although there may be a slight tapering toward the free end as an' aid in withdrawing the core 14 from the completed pipe bend 12.

At the upper end of the tubular form 10 there is provided the cylindrical bell form 16 which is employed to make the usual enlarged socket at one end of the bore of the pipe bend 12. In the illustrated embodiment the bellfonn 16 is carried at one end of a vertical stub shaft 50 which is rotatably and slidably mounted within a fixed sleeve 52, the sleeve 52 being secured to the frame 18 byappropriate brackets 54. A thumb screw 56 is threaded transversely into the sleeve 52 so as to to the main frame 18 in any suitable manner, as by vertical end plate 26. The upper edge of the end plate 26 is fixed to a horizontal sleeve 28 which is rotatably mounted on a shaft 30'so that the plate 26 may be rotated clockwise as viewed in FIG. 1 to permit removal be engageable in either of two annular grooves 58 and 60in the stub shaft 50 andtherehy hold the stub shaft 50 and the bell form 16 in either of two vertical positions. In FIG. 1 the bell form 16 is shown in its down position in which it resides within the mold cavity with its lower surface substantiallyflush with the free end of the core 14. In FIG. 2 the bell form 16 is shown in its up position which permits disassembly of the outer form 10 and removal of the completed pipe bend 12. The upper end of the stub'shaft 50 carries a transverse handle 62 which may be employed manually to rotate the shaft 50 and the bell form 16. The top surface of the bell form 16 carries a horizontal shaper bar 64 which projects over the annular space between the two forms '10 and 16 so as to smooth the end of the pipe bend 12 during rotation of the form 16.

The frame 18 is resiliently mounted on rubber mounts 66 and is provided with a vibrating device 68 such as a conventional electrically operated vibrator which during operation serves to pack the concrete.

In use of the machine the components are first adjusted to the position shown in FIG. 1 and then wet concrete is introduced through a. chute (not shown) into the top of the annular space between the bell form l6 and the outer form 10 so as to fill the latter. The surfaces of the parts which contact the concrete will have been treated with a suitable release agent as is conven- When the Concrete has set sufficiently to be selfsupporting, the arm 26 is rotated at least 90 clockwise about the shaft as viewed in FIG. 1 to thereby move the core out of the form. The form and the completed pipe bend may then be removed from the frame by loosen-' ing the locking arms, swinging the plate and retaining ring clockwise as viewed in FIG. 1 and loosening the locking arm to release the upper end of the form from the frame. The sections of the form are then separated from each other and from the completed pipe bend.

in a preferred configuration as shown in FIG. 1, the outerform is shaped to produce a straight end portion on the pipe bend l2, adapting the end to provide a better joint with a mating bell end than the continuously curved pipe bends formed by conventional devices. The axis of the shaft is centered above the straight end portion and contained in a plane cutting the straight end portion at a right angle. Also, in the example shown, the axis of the shaft 30 is in the same horizontal plane as the bottom of the bell form 16 when it is in its down position, whereby the included angle between the planeof the bell bottom and a plane containing the axis of the shaft 30an'd extending through the center of the straight end portion is a right angle. The mold surface of the end plate 26 is substantially-perpendicular with the straight end portion and is spaced from the axis of the shaft 30 a distance equal to one half of the length of the straight end portion.

What is claimed is:

l. A machine for molding a curved pipe section from castable material comprising: a main frame; an arm pivotally attached at one of its ends to the main frame for swinging movement about a fixed pivot axis; a rigid core of circular cross-section attached at one of its ends to the opposite end of said arm, said core being arcuate with respect to said axis and being tapered from said one end toward its other end; an outer mold form defining a generally arcuate bore of circular cross-section disposed so as to receive said core upon swinging movement of said arm, said outer form being constructed of a plurality of longitudinal sections, the section defining the end of said form remote from said arm being of enlarged cross-section to receive a bell form,

' and the section defining the. end of said outer form nearest said arm having straight walls, said core being secured to said arm by studs, said machine further including an end plate mounted for swinging movement about said pivot axis, said end plate having an aperture through which-said arm extends, and means for securing said end plate against the end of said outer mold form nearest said arm.

2. A machine for molding a curved pipe section from castable material comprising:

a. a frame;

b. an arm pivotally mounted on the main frame for swinging movement about a pivot axis;

0. a rigid core having spaced-apart ends and being attached to said arm at one of said core ends, said core being arcuate about said axis and tapered down toward the core end remote from said arm, and

an outer mold having spaced-apart ends and defining a generally arcuate bore disposed on said frame so as to receive said core upon swinging movement of said arm,

e. one of said mold ends being more remote from said arm than the other of said mold ends, said outer mold being eonstrueted'of longitudinal sections defining said mold ends, the section defining the mold end remote from said arm being of enlarged crosssection for receiving a bell form, the section defining the mold end nearest said arm having straight walls;

f. said pivot axis being contained in a plane cutting said straight walls substantially inwardly of the ends of said last named section and at substantially a right angle thereto. 

1. A machine for molding a curved pipe section from castable material comprising: a main frame; an arm pivotally attached at one of its ends to the main frame for swinging movement about a fixed pivot axis; a rigid core of circular cross-section attached at one of its ends to the opposite end of said arm, said core being arcuate with respect to said axis and being tapered from said one end toward its other end; an outer mold form defining a generally arcuate bore of circular cross-section disposed so as to receive said core upon swinging movement of said arm, said outer form being constructed of a plurality of longitudinal sections, the section defining the end of said form remote from said arm being of enlarged cross-section to receive a bell form, and the section defining the end of said outer form nearest said arm having straight walls, said core being secured to said arm by studs, said machine further including an end plate mounted for swinging movement about said pivot axis, said end plate having an aperture through which said arm extends, and means for securing said end plate against the end of said outer mold form nearest said arm.
 2. A machine for molding a curved pipe section from castable material comprising: a. a frame; b. an arm pivotally mounted on the main frame for swinging movement about a pivot axis; c. a rigid core having spaced-apart ends and being attached to said arm at one of said core ends, said core being arcuate about said axis and tapered down toward the core end remote from said arm, and d. an outer mold having spaced-apart ends and defining a generally arcuate bore disposed on said frame so as to receive said core upon swinging movement of said arm, e. one of said mold ends being more remote from said arm than the other of said mold ends, said outer mold being constructed of longitudinal sections defining said mold ends, the section defining the mold end remote from said arm being of enlarged cross-section for receiving a bell form, the section defining the mold end nearest said arm having straight walls; f. said pivot axis being contained in a plane cutting said straight walls substantially inwardly of the Ends of said last named section and at substantially a right angle thereto. 